1. Field of the Invention
The present invention relates to a connecting device for a wiper blade and the wiper blade having the same.
2. Description of Related Art
A wiper of a vehicle (e.g., an automobile) includes a wiper arm and a wiper blade. The wiper arm is swung by a drive force transmitted from a wiper motor upon energization thereof. The wiper blade is supported by a distal end portion of the wiper arm and contacts a wiping surface of, for example, a front glass (windshield). The wiper blade is connected to and is supported by a hook of the wiper arm, which is placed at a distal end portion of the wiper arm and is configured into a U-shape form, through a connecting member (a connecting device). Japanese Unexamined Patent Publication JP2006-096257A teaches such a connecting member, which connects the wiper blade to the wiper arm.
Specifically, an opening is formed in a longitudinal center portion of a lever member (a holding member) of the wiper blade, and a connecting shaft is securely held in the opening to extend between two side walls of the lever member. A base member of the connecting member is installed to the connecting shaft in the opening of the lever member. The base member includes two side walls and an installation portion. The side walls of the base member contact the side walls of the opening of the lever member. At a location between the side walls of the base member, the installation portion is installed to the hook of the wiper arm. The installation portion is located in one longitudinal side portion of the opening of the lever member to receive the connecting shaft of the lever member. At the other longitudinal side portion of the opening of the lever member, an insertion space is formed between the side walls of the base member and is adapted to receive the hook of the wiper arm. Specifically, a turning portion (arcuate portion) of the hook is inserted into the connecting member through the insertion space and is then moved to the installation portion, so that the installation portion is received in the hook.
In this state, when the hook is moved back to the insertion space, which is opposite from the installation portion in the longitudinal direction, the installed state of the connecting member relative to the hook is released. Therefore, a lock member is provided in the connecting member to lock the connecting member to the hook in the installed state where the installation portion is installed to the hook. The lock member is rotatably installed between the side walls of the base member at a longitudinal end portion of the base member, which is opposite from the installation portion. Furthermore, the lock member includes an engaging piece (an engaging portion). The engaging piece is resiliently flexible and is placed at a longitudinal side (installation portion side) of the lock member, which is opposite from a rotational axis of the lock member. After the installation of the installation portion to the hook, the lock member is rotated to close the insertion space, and the engaging piece is engaged to an outer peripheral surface of the arcuate portion of the hook. In this way, the movement of the hook toward the insertion space is limited by the lock member, and the releasing of the connecting member from the hook is limited to lock the connecting member to the hook.
A plate thickness of the hook of the wiper arm may vary depending on its specification. Specifically, the plate thickness of the hook of the wiper arm may be set to be thick (large) according to its specification. Furthermore, the plate thickness of the hook of the wiper arm may become larger due to presence of a size error caused by a tolerance even in the case where the wiper arm is produced using the same specification. When the plate thickness of the hook is increased, a degree of flexion of the engaging piece of the lock member, which contacts the outer peripheral surface of the hook, is increased. In such a case, a reaction force, which is caused by the increase in the flexion of the engaging piece, is exerted in an unlocking direction of the lock member to promote the unlocking of the lock member. As a result, the lock member may be lifted. Specifically, a portion of the lock member upwardly projects from the wiper blade to deteriorate an appearance of the wiper blade.